#include using namespace std; typedef long long ll; #define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++) #define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++) #define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--) #define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--) #define all(x) (x).begin(), (x).end() #define sz(x) ((ll)(x).size()) #define len(x) ((ll)(x).length()) int main() { cin.tie(0); ios::sync_with_stdio(false); // ifstream in("input.txt"); // cin.rdbuf(in.rdbuf()); string s; cin >> s; ll n = len(s); ll ans = 1; rep(i, n) { ll left = i, right = n - 1 - i; ll tmp = 1; reps(j, 1, min(left, right) + 1) { if (s[i - j] == s[i + j]) { tmp += 2; } } ans = max(ans, tmp); } cout << ans << endl; return 0; }